Google allows automatic captions and translation in all your videos

This is a breakthrough innovation by YouTube, they will, over the coming months, all the videos uploaded and available to all ofus. Videos in languages that do not understand, will be available to us, through subtitling and machine translation.

watch this video on youtube

As Google noted in its YouTube blog, this option is only available to videos in English so far (because its interpretation algorithm audio text is, at present, working in that language), and more languages will come in the coming months.
You must have an audio to be heard clearly to work translating (as the video of Obama in the example)
The errors of interpretation that inevitably appear, may be corrected by the videographer, modifying the text.